/*
 * Copyright (C) 2007-2012 by XDEV Software, All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 3.0 as published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
 
package xdev.db.servlet;


import java.math.BigInteger;
import java.security.CodeSource;
import java.security.MessageDigest;
import java.security.ProtectionDomain;
import java.security.cert.Certificate;


class ServletUtils
{
	private ServletUtils()
	{
	}
	

	static String computeKey(Class clazz)
	{
		try
		{
			ProtectionDomain domain = clazz.getProtectionDomain();
			if(domain == null)
			{
				return null;
			}
			
			CodeSource source = domain.getCodeSource();
			if(source == null)
			{
				return null;
			}
			
			Certificate[] certs = source.getCertificates();
			if(certs == null || certs.length == 0)
			{
				return null;
			}
			
			byte[] key = MessageDigest.getInstance("SHA-1").digest(certs[0].getEncoded());
			return new BigInteger(1,key).toString(Character.MAX_RADIX);
		}
		catch(Throwable t)
		{
			return null;
		}
	}
	

	static String hashKey(String key)
	{
		try
		{
			return new BigInteger(1,MessageDigest.getInstance("SHA-1").digest(key.getBytes("UTF8")))
					.toString(Character.MAX_RADIX);
		}
		catch(Exception e)
		{
			// NoSuchAlgorithmException, UnsupportedEncodingException
			// shouldn't happen
			return key;
		}
	}
}
